 /*******************************************************************************
  * Copyright (c) 2005, 2006 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  * IBM Corporation - initial API and implementation
  *******************************************************************************/
 package org.eclipse.osgi.framework.internal.core;

 import java.io.IOException ;
 import java.net.URL ;
 import java.util.*;

 import org.eclipse.osgi.service.resolver.BundleDescription;
 import org.eclipse.osgi.util.ManifestElement;
 import org.osgi.framework.BundleException;

 /**
  *Registered policy is an implementation of a buddy policy.
  * It is responsible for looking up a class in the bundles (registrant) that declare interest in the bundle that require the buddy loading.
  * Note that the registrants must have a direct dependency on the bundle needing buddy.
  */
 public class RegisteredPolicy extends DependentPolicy {

     public RegisteredPolicy(BundleLoader requester) {
         super(requester);

         //Filter the dependents;
 if (allDependents == null)
             return;

         for (Iterator iter = allDependents.iterator(); iter.hasNext();) {
             BundleLoaderProxy proxy = buddyRequester.getLoaderProxy((BundleDescription) iter.next());
             if (proxy == null)
                 iter.remove();

             try {
                 String [] allContributions = ManifestElement.getArrayFromList((String ) ((AbstractBundle) proxy.getBundle()).getBundleData().getManifest().get(Constants.REGISTERED_POLICY));
                 if (allContributions == null) {
                     iter.remove();
                     continue;
                 }
                 boolean contributes = false;
                 for (int j = 0; j < allContributions.length && contributes == false; j++) {
                     if (allContributions[j].equals(buddyRequester.bundle.getSymbolicName()))
                         contributes = true;
                 }
                 if (!contributes)
                     iter.remove();

             } catch (BundleException e) {
                 iter.remove();
             }
         }

         //After the filtering, if nothing is left then null out the variable for optimization
 if (allDependents.size() == 0)
             allDependents = null;
     }

     public Class loadClass(String name) {
         if (allDependents == null)
             return null;

         Class result = null;
         int size = allDependents.size();
         for (int i = 0; i < size && result == null; i++) {
             try {
                 BundleLoaderProxy proxy = buddyRequester.getLoaderProxy((BundleDescription) allDependents.get(i));
                 if (proxy == null)
                     continue;
                 result = proxy.getBundleLoader().findClass(name, true);
             } catch (ClassNotFoundException e) {
                 //Nothing to do, just keep looking
 continue;
             }
         }
         return result;
     }

     public URL loadResource(String name) {
         if (allDependents == null)
             return null;

         URL result = null;
         int size = allDependents.size();
         for (int i = 0; i < size && result == null; i++) {
             BundleLoaderProxy proxy = buddyRequester.getLoaderProxy((BundleDescription) allDependents.get(i));
             if (proxy == null)
                 continue;
             result = proxy.getBundleLoader().findResource(name, true);
         }
         return result;
     }

     public Enumeration loadResources(String name) {
         if (allDependents == null)
             return null;

         Enumeration results = null;
         int size = allDependents.size();
         for (int i = 0; i < size; i++) {
             try {
                 BundleLoaderProxy proxy = buddyRequester.getLoaderProxy((BundleDescription) allDependents.get(i));
                 if (proxy == null)
                     continue;
                 results = BundleLoader.compoundEnumerations(results, proxy.getBundleLoader().findResources(name));
             } catch (IOException e) {
                 //Ignore and keep looking
 }
         }
         return results;
     }
 }

